C

bio notes 3/5/25

Passive Transport

  • Hypertonic Solution

    • Characterized by a high concentration of solute and low concentration of water.

    • Effect on Cells: Water exits the cell, resulting in cell shrinkage.

      • Red Blood Cells: Cells shrivel due to water loss (termed crenation).

      • Plasma Membrane: The cell membrane shrinks away from the cell wall, a condition referred to as plasmolysis.

Key Terms

  • Crenate: Describes the shrunken state of cells in a hypertonic solution.

  • Turgor: The pressure of the cell contents against the cell wall in a plant cell, maintaining its shape and firmness.

  • Osmoregulate: Mechanisms employed by organisms to maintain water balance.

Active Transport

  • Definition: Movement of molecules across a membrane using energy (ATP).

  • Types of Active Transport:

    • Uses specific proteins to move substances:

      • Uniport: Transports one type of substance in one direction.

      • Symport: Transports two different substances in one direction.

      • Antiport: Transports two different substances in opposite directions.

    • Vesicle Transport: Movement of materials via vesicles:

      • Endocytosis: The process of bringing materials into the cell by forming vesicles.

        • Types of Endocytosis:

          • Phagocytosis: Engulfment of solids (e.g., white blood cells (lymphocytes) engulfing bacteria).

          • Pinocytosis: Engulfment of liquids.

Endosymbiotic Theory

  • Refers to how chloroplasts and mitochondria may have entered early eukaryotic cells as independent prokaryotic organisms, contributing to the development of more complex life.

Importance of Microvilli in Small Intestine

  • Function: Increases surface area for absorption of nutrients (carbohydrates, lipids, proteins).

    • Aids in digestion and absorption processes.

Concept Maps

  • A visual tool for organizing information and facilitating study.

    • Example: Linking cell types (e.g., prokaryotic vs. eukaryotic) and their unique features.